function banner(){
    var i = -1;
    var timer = null;
    
    //定时器自动播放
    timer = setInterval(function () {
        i++;
        if (i == $('.pic').find('.dev').length) {
            i = 0;
        };

        $('.dev').eq(i).animate({
            opacity: 1
        }).siblings().animate({ opacity: 0 })
    }, 4000)

}

module.exports = {
    banner
}